3. Hypoglycemia unawareness as defined by no recognition of hypoglycemia until the glucose is <60 mg/dL and no adrenergic symptoms at glucose of 60 mg/dL (shakiness, palpitations, diaphoresis). Subjects will also be administered the Clark questionnaire for hypoglycemia unawareness. If they have a score ≥ 4, they are excluded from the study